Insects visiting flowers of Olea europaea L. in a Tuscan olive grove were collected and identified in late spring of 2009. A total of 380 specimens belonging to two orders, three families, eight genera and ten species of insects were collected on the flowers. Among Hymenoptera, the numerically dominant species was Apis mellifera L., whose workers were frequently seen to collect pollen from flowers at different times of the day. Moreover, three Halictidae species were identified as foragers on olive flowers: Halictus maculatus Smith, Lasioglossum nitidulum (F.) and Lasioglossum villosulum (Kirby). Among the Diptera, six Syrphidae species, both Syrphinae and Milesiinae, were found on O. europea flowers. ESEM investigation highlighted that all Syrphidae specimens collected in the study presented pollen grains on their mouthparts (between the labella and close to the prestomium). Although further research is necessary, results suggest the potential of O. europea as a source of pollen for a number of insect species, above all in late spring when blossom of other flora is scanty.